The frequency of a certain trait in a population of beetles will increase over time if A. there is variation in that trait within the population.
B. beetles possessing the trait produce more offspring.
C. the trait is not linked to the genetic makeup of the beetle.
D. it creates a specialization to a specific food source.

i don't know, but does anyone wanna be friends? i'm doing my homework at 1: 49 in the morning : /

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.